Change Default Template
 

what table in phpmyadmin can i change the default template?

You don't. Not in the database. You can change the default skin in the admincp. If you want to make changes to the default skin you can do so by logging into your admincp and going to Styles & Languages and then click on the Style Manager. There you will see the default style and you can make changes to it.

I guess i should have explained a bit more, I had a site up a few years back but i lost the site files but still have the DB, i installed a new ver of VB but i think the database is calling for the old template, when i open the site now its just a white page nor can i get to the admincp, I did try the tool.php but it did nothing.

You still should be able to access the acp, by going there directly.
Just remember if you renamed your admin folder, change admincp in the url to the new folder name.

Yeah ozzy is right on where to go, but what you need to do is upload the vbulletin version you were running when you took that site down, so say you were running vB 3.7 you would need to login to your vbulletin.com members area and download vb 3.7, you should still be able to do that. You cannot put a 3.7 database back up and try to run a 4.2 forum off it. You would have to put the version you used last and then upgrade it to the latest version of vbulletin that you want to use. If you put the correct version of files up then you should have no problem logging into the admincp unless the database is corrupted or was corrupted before you took the site down.

Normally, you won't have to do that. Of course you can't login to vB4 using a vB3 database, but you should be able to call the install/upgrade.php directly.

Ah ok yeah that is true and makes sense.